The time it takes to cover the distance between two cities by car varies inversely with the speed of the car. The trip takes

Question

6
hours for a car moving at
30 mph
. How long does the trip take for a car moving at
18 mph
?

Answer 1

We can use the formula for inverse variation:

time = k/speed

where k is a constant of proportionality.

To find k, we can use the information given for the first scenario:

6 = k/30

Multiplying both sides by 30:

k = 180

Now we can use this value of k for the second scenario:

time = 180/18

time = 10

Therefore, the trip takes 10 hours for a car moving at 18 mph.